eslint-plugin-relay is an ESLint plugin that helps enforce Relay best practices in your JavaScript and TypeScript code. It provides rules to ensure proper Relay usage, such as validating GraphQL fragments, ensuring connection specifications adhere to Relay's requirements, and verifying graphql template literal usage. Using this plugin helps maintain consistency and correctness when working with Relay, reducing runtime errors and improving developer experience in large Relay projects. It's crucial for teams employing Relay who want automated enforcement of their coding standards.